require 'diff/lcs' 

seq1 = "a b c e h j l m n p"
seq2 = "b c d e f j k l m r s t"

lcs = Diff::LCS.LCS(seq1, seq2)
diffs = Diff::LCS.diff(seq1, seq2)
sdiff = Diff::LCS.sdiff(seq1, seq2)

#puts lcs.inspect
#puts diffs.inspect
puts sdiff.inspect